The accuracy and efficacy of screening tests for Chlamydia trachomatis: a systematic review

Kanoi B, Kimani R, Maina M, Waweru H, Kamita M, Ndirangu I, M. Abkallo H, Oduor B, Pamme N, Dupaty J, M. Klapperich C, Raju Lolabattu S, Gitaka J. Multi-repeat sequences identification using genome mining techniques for developing highly sensitive molecular diagnostic assay for the detection of Chlamydia trachomatis

Chlamydia trachomatis ( C. trachomatis) is a common sexually transmitted infection (STI). In 2019, the World Health Organization reported about 131 million infections. The majority of infected patients are asymptomatic with cases remaining undetected. It is likely that missed C. trachomatis infections contribute to preventable adverse health outcomes in women and children. Consequently, there is an urgent need of developing efficient diagnostic methods. In this study, genome-mining approaches to identify identical multi-repeat sequences (IMRS) distributed throughout the C. trachomatis genome were used to design a primer pair that would target regions in the genome. Genomic DNA was 10-fold serially diluted (100pg/μL to 1×10 -3pg/μL) and used as DNA template for PCR reactions. The gold standard PCR using 16S rRNA primers was also run as a comparative test, and products were resolved on agarose gel. The novel assay, C. trachomatis IMRS-PCR, had an analytical sensitivity of 4.31 pg/µL, representing better sensitivity compared with 16S rRNA PCR (9.5 fg/µL). Our experimental data demonstrate the successful development of lateral flow and isothermal assays for detecting C. trachomatis DNA with potential use in field settings. There is a potential to implement this concept in miniaturized, isothermal, microfluidic platforms, and laboratory-on-a-chip diagnostic devices for reliable point-of-care testing.

Analytical and clinical validation of a multiplex PCR assay for detection of Neisseria gonorrhoeae and Chlamydia trachomatis including simultaneous LGV serotyping on an automated high-throughput PCR system

For effective infection control measures for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG), a reliable tool for screening and diagnosis is essential. Here, we aimed to establish and validate a multiplex PCR assay on an automated system using a dual-target approach for the detection of CT/NG and differentiation between lymphogranuloma venereum (LGV) and non-LGV from genital and extra-genital specimens. Published primer/probe sets (CT: pmpH, cryptic plasmid; NG: porA, opa) were modified for the cobas 5800/6800/8800. Standards quantified by digital PCR were used to determine linearity and lower limit of detection (LLoD; eSwab, urine). For clinical validation, prospective samples (n = 319) were compared with a CE-marked in vitro diagnostics (CE-IVD) assay. LLoDs ranged from 21.8 to 244 digital copies (dcp)/mL and 10.8 to 277 dcp/mL in swab and urine, respectively. A simple linear regression analysis yielded slopes ranging from -4.338 to -2.834 and Pearson correlation coefficients from 0.956 to 0.994. Inter- and intra-run variability was <0.5 and <1 cycle threshold (ct), respectively. No cross-reactivity was observed (n = 42). Clinical validation showed a sensitivity of 94.74% (95% confidence interval (CI): 87.23%-97.93%) and 95.51% (95% CI: 89.01%-98.24%), a specificity of 99.59% (95% CI: 97.71%-99.98%) and 99.57% (95% CI: 97.58%-99.98%), positive predictive values of 89.91% (estimated prevalence: 3.7%; 95% CI: 80.91%-95.6%) and 88.61% (estimated prevalence: 3.4%; 95% CI: 80.18%-94.34%), and negative predictive values of 99.81% (95% CI: 98.14%-100%) and 99.85% (95% CI: 98.14%-100%) for the detection of CT and NG, respectively. In conclusion, we established a dual-target, internally controlled PCR on an automated system for the detectiwon of CT/NG from genital and extra-genital specimens. Depending on local regulations, the assay can be used as a screening or a confirmatory/typing assay.IMPORTANCEChlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) represent a major global health burden, with the World Health Organization estimating that >128 million and >82 million people, respectively, were newly infected in 2020. For effective infection control measures, a reliable tool for sensitive diagnosis and screening of CT/NG is essential. We established a multiplex PCR assay for the detection of CT/NG and simultaneous discrimination between lymphogranuloma venereum (LGV) and non-LGV strains, which has been validated for genital and extra-genital specimens on a fully automated system. To increase assay sensitivity, a dual-target approach has been chosen for both pathogens. This strategy reduces false-positive results in oropharyngeal swabs due to the detection of commensal N. species that may harbor NG DNA fragments targeted in the PCR due to horizontal gene transmission following previous infection. In sum, the established assay provides a powerful tool for use as either a screening/diagnostic or a typing/confirmatory assay.

An isothermal CRISPR-based diagnostic assay for Neisseria gonorrhoeae and Chlamydia trachomatis detection

IMPORTANCE

A method for Neisseria gonorrhoeae (NG)/Chlamydia trachomatis (CT) detection is developed using multiplex-recombinase polymerase amplification and Cas12a/Cas13a. This method can detect NG and CT simultaneously with high sensitivity and specificity. This method has great potential to be further developed into larger-scale screening and point-of-care testing (POCT).

The Influence of Screening, Misclassification, and Reporting Biases on Reported Chlamydia Case Rates Among Young Women in the United States, 2000 Through 2017

BACKGROUND

National chlamydia case rate trends are difficult to interpret because of biases from partial screening coverage, imperfect diagnostic tests, and underreporting. We examined the extent to which these time-varying biases could influence reported annual chlamydia case rates.

METHODS

Annual reported case rates among women aged 15 through 24 years from 2000 through 2017 were obtained from the Centers for Disease Control and Prevention's National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention AtlasPlus tool. Estimates of reporting completeness, diagnostic test sensitivity and specificity, and screening coverage were derived from literature review and expert opinion. We adjusted annual reported case rates for incomplete reporting, imperfect diagnostic tests, and partial screening coverage through a series of corrections, and calculated annual adjusted case rates of correctly diagnosed chlamydia.

RESULTS

Adjusted chlamydia case rates among young women were higher than reported case rates throughout the study period. Reported case rates increased over the study period, but adjusted rates declined from 12,900 to 7900 cases per 100,000 person-years between 2000 and 2007. After 2007, adjusted case rates declined to 7500 cases per 100,000 person-years in 2017. Bias from partial screening coverage had a larger impact on case rate magnitude and trend shape than bias from imperfect diagnostic tests or underreporting.

CONCLUSIONS

Reported chlamydia case rates may be substantially lower than true chlamydia case rates because of incomplete reporting, imperfect diagnostic tests, and partial screening coverage. Because the magnitude of these biases has declined over time, the differences between reported and adjusted case rates have narrowed, revealing a sharp decline in adjusted case rates even as reported case rates have risen. The decline in adjusted case rates suggests that the rise in reported case rates should not be interpreted strictly as increasing chlamydia incidence, as the observed rise can be explained by improvements in screening coverage, diagnostic tests, and reporting.

Rapid multiplex PCR assay for simultaneous detection of Neisseria gonorrhoeae and Chlamydia trachomatis in genitourinary samples: A 30-minute assay

We developed a rapid multiplex PCR assay available in bedside for the simultaneous detection of Neisseria gonorrhoeae and Chlamydia trachomatis, which enables diagnosis in less than 30 minutes. In this study, we validated the clinical utility of this assay including its sensitivity and specificity for NG and CT detection.

Update on the Diagnosis of Sexually Transmitted Infections

Sexually transmitted infections (STIs) are one of the most frequent and universal Public Health problems. Health professionals should be aware of the possibility of STIs due to their high morbidity and the presence of sequelae. The delay in the diagnosis is one of the factors that justifies the difficulty to infections control. Diagnostic tests allow the introduction of aetiological treatment and also lead to treating symptomatic and asymptomatic patients more effectively, as well as to interrupt the epidemiological transmission chain without delay. In this review we have made an update of the main existing diagnostic methods for the more important STIs.

Detection of chlamydia trachomatis infection among the pregnant women attending a tertiary care hospital in Kerala - South India by polymerase chain reaction

Background

Chlamydia trachomatis infection is the most prevalent bacterial sexually transmitted infection and may influence pregnancy outcome.

Aims and Objectives

This study was conducted to assess Chlamydial infection during pregnancy by PCR.

Materials and Methods

Study group consists of patients who are attending the antenatal clinics. Endocervical swabs were collected from 300 patients.

Results

Off the 300 samples tested, 29 were positive as per PCR which used CT F : 5' CGT GTC GGC AAT CCT GCT GAT 3' and CT R : 5' GTC GAT AAC ATA GTC ACG ATA GTC 3'as the primers.

Conclusion

This suggests there is a prevalence of Chlamydia trachomatis in our population which is 10%. Hence, it should be noted as a significant public health problem especially among sexually active young women of child bearing age. Timely detection and prompt treatment of Chlamydial infection during pregnancy can eliminate its adverse outcomes.

Rapid and accurate diagnosis of Chlamydia trachomatis in the urogenital tract by a dual-gene multiplex qPCR method

Introduction. Chlamydia trachomatis (C. trachomatis, CT) is an obligatory intracellular bacterium that causes urogenital tract infections and leads to severe reproductive consequences. Therefore, a rapid and accurate detection method with high sensitivity and specificity is an urgent requirement for the routine diagnosis of C. trachomatis infections.Aim. In this study, we aimed to develop a multiplex quantitative real-time PCR (qPCR) assay based on two target regions for accurate detection of C. trachomatis in urogenital tract infections.Methodology. Primers and probes based on the conserved regions of the cryptic plasmid and 23S rRNA gene were designed. Then, two qPCR assays were established to screen for the optimal probe and primers for each of the two target regions. Subsequently, the multiplex qPCR method was developed and optimized. For the diagnostic efficiency evaluation, 1284 urogenital specimens were tested by the newly developed multiplex qPCR method, an immunological assay and a singleplex qPCR assay widely used in hospitals.Results. The multiplex qPCR method could amplify both target regions in the range of 1.0×10²-1.0×10⁸ copies ml^-1 with a strong linear relationship, and lower limits of detection (LODs) for both targets reached 2 copies PCR^-1. For the multiplex qPCR method, the diagnostic sensitivity and specificity was 100.0 % (134/134) and 99.3 % (1142/1150), respectively. For the singleplex qPCR assay, the diagnostic sensitivity and specificity was 88.8 % (119/134) and 100.0 % (1150/1150), respectively. For the immunological assay, the diagnostic sensitivity and specificity was 47.0 % (63/134) and 100.0 % (1150/1150), respectively.Conclusion. In this study, a multiplex qPCR assay with high sensitivity and specificity for rapid (≤2.0 h) and accurate diagnosis of C. trachomatis was developed. The qPCR assay has the potential to be used as a routine diagnostic method in clinical microbiology laboratories.

Relationship between Chlamydia Trachomatis Infection with Patency Tubal and Non-Patency Tubal Occurrence in Infertile Women

AIM

To determine the relationship between Chlamydia Trachomatis infections with patency tubal and non-patency tubal occurrence in infertile women.

METHODS

This research was an observational analytic research with a cross-sectional study. This research was conducted at Haji Adam Malik General Hospital Medan, Pramita Laboratory Medan and Medical Faculty of Medicine Universitas Sumatera Utara. Laboratory on October 2017 until the number of samples was fulfilled. The samples were women who were referred to Pramita Laboratory Medan for hysterosalpingography procedure in accordance which corresponded to the inclusion criteria by using consecutive sampling technique.

RESULTS

From this research, it was found that the most infertile women were aged 31-35 years, with the most infertility type was primary infertility (83,8%) with the longest infertility duration was ≥ 3 years (44%). From all samples who were infertile, 26% among them were positive to chlamydia infection. Eight from twelve people who were infected by Chlamydia Trachomatis experienced non-patency tubal (66.7%) with p-value = 0.001 which showed that there was a relationship between Chlamydia Trachomatis infection with patency tubal and non-patency tubal occurrence in infertile women.

CONCLUSION

The proportion of Chlamydia Trachomatis infection in tubal abnormality in this study was 66.7%, whereas Chlamydia Trachomatis infection in the normal tube was 13.2%. It was obtained that there was a significant relationship between Chlamydia Trachomatis infection with tubal abnormality (non-patency tubal) with p-value < 0.005 (p = 0.001).

Cervicitis: Etiology, diagnosis and treatment

Cervicitis is the inflammation of the cervix. It is usually caused by an infectious agent, usually sexually transmitted. Cervicitis is frequently asymptomatic and silent infection can cause complications of the upper genital tract. The symptoms are usually nonspecific, the most significant being an increase in vaginal discharge and/or intermenstrual bleeding. For its diagnosis, there are commercial systems based on molecular techniques that include almost all of the known pathogens associated with cervicitis, although cultures should not be abandoned due to the need to conduct studies of susceptibility to antibiotics. It is recommended to initiate an empirical antibiotic therapy that covers C.trachomatis and N.gonorrhoeae in the case of women at high risk of infection by these pathogens, especially if the follow-up is not assured or adequate diagnostic tests are not available. In women with low risk of sexually transmitted infection, antibiotic therapy should be adjusted to the results of the microbiological results.

Prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae infections among pregnant women and eye colonization of their neonates at birth time, Shiraz, Southern Iran

Background

Chlamydia trachomatis and Neisseria gonorrhoeae are the two common transmissible pathogens from pregnant women to their neonates. Given the lack of routine screening and treatment of pregnant women in some areas, the possibility of transmission rises. This study seeks to determine the prevalence of C. trachomatis and N. gonorrhoeae in the pregnant women with no clinical symptoms and the vertical transmission rate to their neonates.

Methods

The study was conducted on endocervical and eye swab samples of 239 pregnant women and their neonates. Identification was based on PCR method.

Results

The prevalence rates of C.trachomatis in women and neonates were 37/239 (15.5%) and 28/239 (11.7%), and for N. gonorrhoeae 3/239 (1.3%), 1/239 (0.4%), respectively. The vertical transmission rates to the neonates were 28/37(75.6%) for C. trachomatis and 1/3 for N. gonorrhoeae.

Conclusions

In the areas with a high prevalence of chlamydial or gonococcal infections, and in the absence of screening and treatment of the pregnant women, ocular prophylaxis with antibiotics is suggested as a part of routine neonatal care program for the prevention of chlamydial and gonococcal ophthalmia.

Accuracy of tests used to detect infection with Chlamydia trachomatis in asymptomatic pregnant women: a systematic review

PURPOSE OF REVIEW

Infection with Chlamydia trachomatis in pregnancy is linked to increased risk of miscarriage, stillbirth, and preterm birth. Currently, PCR or DNA-based tests are the gold standard when detecting the infection; however, they are costly and require access to specialist equipment. The aim of this systematic review was to assess the accuracy of available tests to detect infection in an asymptomatic pregnant population.

RECENT FINDINGS

There was evidence of the superior accuracy of nucleic acid amplification tests to cell culture in nonpregnant asymptomatic women; however, there are multiple commercial nucleic acid amplification tests with varying sensitivities and specificities. There is a gap in current literature on accuracy studies in an asymptomatic pregnant population, particularly within routine antenatal settings.

SUMMARY

There is a need for a point-of-care test for Chlamydia in pregnancy. Future test accuracy studies for this population should aim to use a universally established reference standard. Further research should provide relevant evidence to guide practice.

A PRISMA systematic review and meta-analysis on Chlamydia trachomatis infections in Iranian women (1986-2015)

BACKGROUND

Chlamydia trachomatis (CT) is the cause of genital tract infections in women. Some evidence has shown the role of this infection with CT in spontaneous abortions. The purpose of this study is to study the frequency of CT infection in Iranian women.

METHODS

This study was performed based on PRISMA guidelines. A total of 75 articles published in Google Scholar, PubMed, ISI Web of Science, Biological abs, Iranmedex, SID, and Scopus databases were found (1986-2015) using the following keywords: CT in women, CT and Iranian women, CT and infection in Iran, CT and pregnancy in Iran, CT and preterm delivery in Iran, CT and preterm labor in Iran, CT and fertility in Iran, CT and infertility in Iran, and CT and abortion in Iran. Finally, 40 studies from different regions of Iran were included. Statistical analyses were performed using R3 and STATA 12.

RESULTS

From 1986 to 2015, the lowest rate of prevalence was from 2010 to 2011 (3.9%) and the highest prevalence rate was in 2009 (69.39%) in northern Iran. Fixed effects for different parts of Iran (North, South, East, and West) were Pooled proportion: 0.13 (95% confidence interval [CI] = 0.12-0.14) and for samples (cervical, vaginal, urine, and blood) the pooled proportion was = 0.14 (95% CI = 0.12-0.14).

CONCLUSION

CT infection in this study was prevalent in urine samples and the rate of CT was observed from culture methods in comparison to other methods. Because women with CT play an important role because of sexual activity for transmission and untreated women are at risk of developing sequels. Also, most studies in Iran use sensitive polymerase chain reaction tests for the detection of genital CT infections.

Striking ethnic variations in the epidemiology of Chlamydia trachomatis in Haifa District, Israel, throughout the years 2001-2015

Our objectives were to examine trends in the incidence of chlamydia over an extended period and compare the epidemiology of the infection between two distinct ethnic groups in Israel: Jews and Arabs. We examined the incidence rate of Chlamydia trachomatis infection among residents of Haifa District, northern Israel from 2001 to 2015, by reviewing archives of the Department of Epidemiology, Ministry of Health. Notified cases were stratified by age group, gender, and ethnic group. The overall incidence rate of Chlamydia was 10.8 cases per 100,000 population per year. The annual rate increased dramatically from 5.1 per 100,000 population in 2001, to an all-time high of 18.5 cases per 100,000 population in 2015 (P < 0.001), representing an increase of 362.7%. The most affected age group was 25-34 years of age. The estimated rate among Jewish inhabitants was ninefold higher than among Arabs. Only 3% recurrent episodes of Chlamydia were registered. The prevalence of HIV positivity among Chlamydia-infected patients was similar to that of the general population. In conclusion, Chlamydia in Haifa has been continuously increasing since 2001 and the infection is much more prevalent among patients of Jewish ethnicity, mainly due to more hazardous sexual practices in this population.

Chlamydia trachomatis infection in young pregnant women in Southern Brazil: a cross-sectional study

This study estimated the prevalence of Chlamydia trachomatis infection during pregnancy in a sample of women up to 29 years of age in the city of Pelotas, Rio Grande do Sul State, Brazil, and investigated socio-demographic risk factors such as maternal age, marital status, maternal schooling, and family income. C. trachomatis infection was diagnosed with PCR using BD ProbeTecTM CT/GC Amplified DNA Assay. Socio-demographic, behavioral, and reproductive data were collected using structured questionnaires. All collections were performed by previously trained medical students. The study included a stratified probabilistic sample from four maternity hospitals in the city. The sample included 562 pregnant women, and prevalence of C. trachomatis infection was 12.3% (95%CI: 9.6-15.0). No significant association was identified between C. trachomatis infection and any of the target variables, including obstetric outcomes such as history of preterm delivery. Our findings in terms of low treatment adherence, only 43% of the women and 9.7% of partners, associated with high C. trachomatis prevalence, reinforce the need to implement routine screening for C. trachomatis during prenatal care. The attempt to diagnose and treat this infection after delivery, as in this study, limits the possibility of success.

The natural history of Chlamydia trachomatis infection in women: a multi-parameter evidence synthesis

BACKGROUND AND OBJECTIVES

The evidence base supporting the National Chlamydia Screening Programme, initiated in 2003, has been questioned repeatedly, with little consensus on modelling assumptions, parameter values or evidence sources to be used in cost-effectiveness analyses. The purpose of this project was to assemble all available evidence on the prevalence and incidence of Chlamydia trachomatis (CT) in the UK and its sequelae, pelvic inflammatory disease (PID), ectopic pregnancy (EP) and tubal factor infertility (TFI) to review the evidence base in its entirety, assess its consistency and, if possible, arrive at a coherent set of estimates consistent with all the evidence.

METHODS

Evidence was identified using 'high-yield' strategies. Bayesian Multi-Parameter Evidence Synthesis models were constructed for separate subparts of the clinical and population epidemiology of CT. Where possible, different types of data sources were statistically combined to derive coherent estimates. Where evidence was inconsistent, evidence sources were re-interpreted and new estimates derived on a post-hoc basis.

RESULTS

An internally coherent set of estimates was generated, consistent with a multifaceted evidence base, fertility surveys and routine UK statistics on PID and EP. Among the key findings were that the risk of PID (symptomatic or asymptomatic) following an untreated CT infection is 17.1% [95% credible interval (CrI) 6% to 29%] and the risk of salpingitis is 7.3% (95% CrI 2.2% to 14.0%). In women aged 16-24 years, screened at annual intervals, at best, 61% (95% CrI 55% to 67%) of CT-related PID and 22% (95% CrI 7% to 43%) of all PID could be directly prevented. For women aged 16-44 years, the proportions of PID, EP and TFI that are attributable to CT are estimated to be 20% (95% CrI 6% to 38%), 4.9% (95% CrI 1.2% to 12%) and 29% (95% CrI 9% to 56%), respectively. The prevalence of TFI in the UK in women at the end of their reproductive lives is 1.1%: this is consistent with all PID carrying a relatively high risk of reproductive damage, whether diagnosed or not. Every 1000 CT infections in women aged 16-44 years, on average, gives rise to approximately 171 episodes of PID and 73 of salpingitis, 2.0 EPs and 5.1 women with TFI at age 44 years.

CONCLUSIONS AND RESEARCH RECOMMENDATIONS

The study establishes a set of interpretations of the major studies and study designs, under which a coherent set of estimates can be generated. CT is a significant cause of PID and TFI. CT screening is of benefit to the individual, but detection and treatment of incident infection may be more beneficial. Women with lower abdominal pain need better advice on when to seek early medical attention to avoid risk of reproductive damage. The study provides new insights into the reproductive risks of PID and the role of CT. Further research is required on the proportions of PID, EP and TFI attributable to CT to confirm predictions made in this report, and to improve the precision of key estimates. The cost-effectiveness of screening should be re-evaluated using the findings of this report.

FUNDING

The Medical Research Council grant G0801947.

Evaluation of screening for Chlamydia trachomatis among young women in primary health care services in Manaus, Amazonas State, Brazil

Screening for Chlamydia trachomatis is not routinely offered to young asymptomatic women in Brazil. This study evaluated the performance, usefulness, and operational suitability of the Digene Hybrid Capture II (HCII) CT-ID DNA-test as an opportunistic screening tool to detect C. trachomatis in the public health system in Manaus, Amazonas State. Women aged 14-25 years who attended primary health care services were interviewed and one cervical specimen was collected during cytological screening. The HCII CT test was evaluated for its ability to detect the presence of C. trachomatis and against real-time PCR (q-PCR) in a subset of samples. Operational performance was assessed through interviews with providers and patients. Overall, 1,187 women were screened, and 1,169 had a HCII CT-ID test result (292 of these were also tested by q-PCR). Of those, 13.1% (n = 153) were positive. The sensitivity, specificity, positive and negative predictive values of HCII CT were 72.3% (95%CI: 65.4-78.6), 91.3% (95%CI: 84.1-95.9), 93.8% (95%CI: 88.5-97.1), and 64.4% (95%CI: 56.0-72.1), respectively. Sample collection caused discomfort in 19.7% of women. Among health professionals (n = 52), the main barriers reported included positive cases who did not return for results (56.4%), unwillingness to screen without an appointment (45.1%), and increase in their workload (38.8%). HCII CT-ID identified a high proportion of C. trachomatis cases among young women in Manaus. However, its moderate sensitivity limits its use as an opportunistic screening tool in primary health care settings in Manaus. Screening was well accepted although the barriers we identified, especially among health professionals, challenge screening detection and treatment efforts.

Background review for the '2015 European guideline on the management of Chlamydia trachomatis infections'

SummaryChlamydia trachomatis infections are major public health concerns globally. Of particular grave concern is that the majority of persons with anogenital Chlamydia trachomatis infections are asymptomatic and accordingly not aware of their infection, and this silent infection can subsequently result in severe reproductive tract complications and sequelae. The current review paper provides all background, evidence base and discussions for the 2015 European guideline on the management of Chlamydia trachomatis infections (Lanjouw E, et al. Int J STD AIDS 2015). Comprehensive information and recommendations are included regarding the diagnosis, treatment and prevention of anogenital, pharyngeal and conjunctival Chlamydia trachomatis infections in European countries. However, Chlamydia trachomatis also causes the eye infection trachoma, which is not a sexually transmitted infection. The 2015 European Chlamydia trachomatis guideline provides up-to-date guidance regarding broader indications for testing and treatment of Chlamydia trachomatis infections; clearer recommendation of using validated nucleic acid amplification tests only for diagnosis; advice on (repeated) Chlamydia trachomatis testing; recommendation of increased testing to reduce the incidence of pelvic inflammatory disease and prevent exposure to infection and recommendations to identify, verify and report Chlamydia trachomatis variants. Improvement of access to testing, test performance, diagnostics, antimicrobial treatment and follow-up of Chlamydia trachomatis patients are crucial to control its spread.

2015 European guideline on the management of Chlamydia trachomatis infections

Chlamydia trachomatis infections, which most frequently are asymptomatic, are major public health concerns globally. The 2015 European C. trachomatis guideline provides: up-to-date guidance regarding broader indications for testing and treatment of C. trachomatis infections; a clearer recommendation of using exclusively-validated nucleic acid amplification tests for diagnosis; advice on (repeated) C. trachomatis testing; the recommendation of increased testing to reduce the incidence of pelvic inflammatory disease and prevent exposure to infection; and recommendations to identify, verify and report C. trachomatis variants. Improvement of access to testing, test performance, diagnostics, antimicrobial treatment and follow-up of C. trachomatis patients are crucial to control its spread. For detailed background, evidence base and discussions, see the background review for the present 2015 European guideline on the management of Chlamydia trachomatis infections (Lanjouw E, et al. Int J STD AIDS. 2015).

High dynamic range detection of Chlamydia trachomatis growth by direct quantitative PCR of the infected cells

Chlamydiae are obligate intracellular bacteria developing in an intracytoplasmic niche, the inclusion. Chlamydia growth measurement by inclusion counting is a key task in the development of novel antichlamydial antibiotics and in vaccine studies. Most of the current counting methods rely on the immunofluorescent staining of the inclusions and either manual or automatic microscopy detection and enumeration. The manual method is highly labor intensive, while the automatic methods are either medium-throughput or require automatic microscopy. The sensitive and specific PCR technology could be an effective method for growth related chlamydial DNA detection; however the currently described PCR approaches have a major limitation, the requirement of purification of DNA or RNA from the infected cells. This limitation makes this approach unfeasible for high-throughput screenings. To overcome this, we developed a quantitative PCR (qPCR) method for the detection of Chlamydia trachomatis DNA directly from the infected HeLa cells. With our method we were able to detect the bacterial growth in a 4 log scale (multiplicity of infection (MOI): 64 to 0.0039), with high correlation between the biological and technical replicates. As a further proof of the method, we applied the direct qPCR for antibiotic minimum inhibitory concentration (MIC) measurements. The measured MICs of moxifloxacin, tetracycline, clarithromycin and compound PCC00213 were 0.031 μg/ml, 0.031 μg/ml, 0.0039 μg/ml and 6.2 μg/ml respectively, identical or close to the already published MIC values. Our direct qPCR method for chlamydial growth and antibiotic MIC determination is less time-consuming, more objective and more sensitive than the currently applied manual or automatic fluorescent microscopy- based methods.

Diagnostic accuracy of rapid tests for sexually transmitted infections in symptomatic women

OBJECTIVE

To determine the diagnostic accuracy of tests developed for use at the point of care for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and syphilis in women having symptoms of lower urinary tract infection.

METHODS

Cross-sectional study involving sexually active 14-49-year-old women with lower urinary tract infection symptoms consulting during 2010 at a private health clinic and at two public hospitals in Bogotá, Colombia. Pregnant women, those with a previous hysterectomy or those who received antibiotics during the previous 7 days were excluded. Sequential sampling was used; sample size: 1500 women. The ACON NG and CT duo test combo and the ACON individual test plates for NG and separately for CT were used. The QuickVue Chlamydia rapid test (RT) was also used. All of them were compared with nucleic acid amplification methods. The SD Bioline 3.0 and ACON test for syphilis were evaluated and compared with serological tests. Sensitivity and specificity were estimated.

RESULTS

CT RTs had a sensitivity that ranged between 22.7% and 37.7% and specificity between 99.3% and 100%. Sensitivity for NG with ACON Duo was 12.5% and specificity 99.8%. Tests for syphilis had a sensitivity of 91.6-100% and a specificity of 99.7-97.8%.

CONCLUSIONS

The RTs studied are not useful for screening for NG at the point of care. In case of CT a recommendation about their use in routine care should be supported by a cost-effectiveness analysis. In screening populations at high risk of sexually transmitted infections or pregnant women, the RTs for syphilis should be used.

Screening for Chlamydia trachomatis in Egyptian women with unexplained infertility, comparing real-time PCR techniques to standard serology tests: case control study

BACKGROUND

To study the prevalence of Chlamydia infection in women with primary and secondary unexplained infertility using ELISA technique for antibody detection and real time, fully automated PCR for antigen detection and to explore its association with circulating antisperm antibodies (ASA).

METHODS

A total of 50 women with unexplained infertility enrolled in this case control study and a control group of 44 infertile women with a known cause of infertility. Endocervical specimens were collected for Chlamydia antigen detection using PCR and serum samples for antibodies detection. Circulating anti-sperm antibodies were detected using sperm antibody Latex Agglutination tests.

RESULTS

The overall prevalence of Chlamydial infection in unexplained infertility cases as detected by both ELISA and PCR was 40 % (20/50). The prevalence of current Chlamydial genital infection as detected by real-time PCR was only 6.0 % (3/50); two of which were also IgM positive. Prevalence of ASA was 6.0 % (3/50); all were sero-negative for anti-C.trachomatis IgM and were PCR negative.

CONCLUSION

The incidence of Chlamydial infection in Egyptian patients with unexplained infertility is relatively high. In the setting of fertility investigations; screening for anti. C.trachomatis antibodies using ELISA, and treatment of positive cases should be considered. The presence of circulating ASA does not correlate with the presence of old or current Chlamydia infection in women with unexplained infertility.

Urogenital chlamydia infection in women: patient management tactics according to present-day foreign and Russian recommendations

The article present data on current approaches to laboratory diagnostics and treatment of urogenital chlamydia infection in women. According to Russian and foreign guidelines, azithromycin, josamycin and doxycycline monohydrate belong to the most efficient antimicrobial drugs for the treatment of urogenital chlamydia infection in non-pregnant women. As for the treatment of pregnant patients suffering from this pathology, azithromycin and josamycin are the most optimal drugs in terms of safety and treatment efficacy according to both Russian and foreign guidelines.

Antenatal lower genital tract infection screening and treatment programs for preventing preterm delivery

BACKGROUND

Genital tract infection is associated with preterm birth (before 37 weeks' gestation). Screening for infections during pregnancy may therefore reduce the numbers of babies being born prematurely. However, screening for infections may have some adverse effects, such as increased antibiotic drug resistance and increased cost of treatment.

OBJECTIVES

To assess the effectiveness of antenatal lower genital tract infection screening and treatment programs for reducing preterm birth and subsequent morbidity.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 November 2014), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2014, Issue 7) and reference lists of retrieved reports.

SELECTION CRITERIA

We included all published and unpublished randomised controlled trials in any language that evaluated any described methods of antenatal lower genital tract infection screening compared with no screening.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked for accuracy.

MAIN RESULTS

One study (4155 women at less than 20 weeks' gestation) met the inclusion criteria. The intervention group (2058 women) received infection screening and treatment for bacterial vaginosis, trichomonas vaginalis and candidiasis; the control group (2097 women) also received screening, but the results of the screening program were not revealed and women received routine antenatal care. The rate of preterm birth before 37 weeks' gestation was significantly lower in the intervention group (3% versus 5% in the control group) with a risk ratio (RR) of 0.55 (95% confidence interval (CI) 0.41 to 0.75; the evidence for this outcome was graded as of moderate quality). The incidence of preterm birth for infants with a weight equal to or below 2500 g (low birthweight) and infants with a weight equal to or below 1500 g (very low birthweight) were significantly lower in the intervention group than in the control group (RR 0.48, 95% CI 0.34 to 0.66 and RR 0.34; 95% CI 0.15 to 0.75, respectively; both graded as moderate quality evidence). Based on a subset of costs for preterm births of < 1900 g, the authors reported that for each of those preterm births averted, EUR 60,262 would be saved.

AUTHORS' CONCLUSIONS

There is evidence from one trial that infection screening and treatment programs for pregnant women before 20 weeks' gestation reduce preterm birth and preterm low birthweight. Infection screening and treatment programs are associated with cost savings when used for the prevention of preterm birth. Future trials should evaluate the effects of different types of infection screening programs.

Highly sensitive and novel point-of-care system, aQcare Chlamydia TRF kit for detecting Chlamydia trachomatis by using europium (Eu) (III) chelated nanoparticles

Background

The bacterium Chlamydia trachomatis is one of the leading causes of sexually transmitted diseases worldwide. Since no simple and effective tool exists to diagnose C. trachomatis infections, we evaluated a novel point-of-care (POC) test, aQcare Chlamydia TRF kit, which uses europium-chelated nanoparticles and a time-resolved fluorescence reader.

Methods

The test performance was evaluated by comparing the results obtained using the novel POC testing kit with those obtained using a nucleic acid amplification test (NAAT), using 114 NAAT-positive and 327 NAAT-negative samples.

Results

The cut-off value of the novel test was 20.8 with a detection limit of 0.27 ng/mL. No interference or cross-reactivity was observed. Diagnostic accuracy showed an overall sensitivity of 93.0% (106/114), specificity of 96.3% (315/327), positive predictive value (PPV) of 89.8% (106/118), and negative predictive value (NPV) of 97.5% (315/323). The sensitivity of the novel test was much higher than that of currently available POC tests. Furthermore, the relative ease and short turnaround time (30 min) of this assay enables C. trachomatis-infected individuals to be treated without a diagnostic delay.

Conclusions

This simple and novel test is a potential tool to screen a larger population, especially those in areas with limited resources.

Screening tests: a review with examples

Screening tests are widely used in medicine to assess the likelihood that members of a defined population have a particular disease. This article presents an overview of such tests including the definitions of key technical (sensitivity and specificity) and population characteristics necessary to assess the benefits and limitations of such tests. Several examples are used to illustrate calculations, including the characteristics of low dose computed tomography as a lung cancer screen, choice of an optimal PSA cutoff and selection of the population to undergo mammography. The importance of careful consideration of the consequences of both false positives and negatives is highlighted. Receiver operating characteristic curves are explained as is the need to carefully select the population group to be tested.

Application of HTB-SiHa cells transfected with a recombinant plasmid for external quality assessment of Chlamydia trachomatis PCR

Background

The participation of laboratories in external quality assessment (EQA) programs is required for the quality assurance of nucleic acid amplification of Chlamydia trachomatis. This study aimed to construct a new quality control (QC) material applicated in EQA of C. trachomatis PCR.

Methods

A QC material-HTB-SiHa cells transfected with a recombinant plasmid containing the cryptic plasmid sequence-was constructed for C. trachomatis PCR detection, and four different panels, each consisting of 4 positive samples with serial dilution of the constructed QC material and 1 negative sample, were distributed by the National Center for Clinical Laboratories among four groups of 275, 268, 317, and 304 participants across China from 2011 through 2012. A total of eight commercial kits were used for C. trachomatis PCR detection in participants.

Results

Nine laboratories reported false-positive results (0.9%). As the series dilution increased, the correct reporting of the data sets decreased; the lowest correct rate was 96.3% in the weakest positive samples (10⁴ copies/mL). Eight laboratories reported false-positive results, and 42 laboratories reported false-negative results in the EQA detection of C. trachomatis. No significant differences were observed in the detection of the constructed C. trachomatis positive samples (97.9%, 98.5%, 100%, 98.5%; P=0.36) and negative samples (100%, 99.0%, 100%, 99.0%; P=0.764) using four commercial kits commonly used in China.

Conclusions

The results of the EQA study indicated that the constructed material provides a noninfectious, stable control material with sufficient volume for PCR detection of C. trachomatis.

Screening for Chlamydia infection in a sexually transmitted infection clinic: a missed opportunity?

OBJECTIVES

Chlamydia trachomatis (CT) infection is the most common sexually transmitted infection (STI) reported in Europe. We aim to evaluate the overall prevalence of CT infection and the rate of asymptomatic infection in an STI clinic over a 5-year period. We will also discuss screening strategies with reference to attendees diagnosed with an STI and their sexual partners, and attendees with a non-infectious genital dermatosis.

METHODS

Clinical and laboratory data for all attendees at a university hospital STI clinic over a 5-year period were reviewed. Diagnosis of CT infection was made upon polymerase chain reaction (PCR) performed in first-void urine.

RESULTS

The overall prevalence of CT infection was 4.0% (53/1310); the rate of asymptomatic infection was 84.9% (45/53). The prevalence of CT infection among attendees with an STI diagnosis and their sexual partners was 5.2% (50/963), whereas that among attendees with a non-infectious genital dermatosis was 0.9% (3/347; P < 0.001). Infected attendees were younger than attendees without CT infection (median age: 31 years vs. 40 years; P < 0.001). In 39.5% (17/43) of CT-infected attendees, it was possible to notify a sexual partner; CT infection was subsequently diagnosed in 58.8% (10/17) of partners.

CONCLUSIONS

Asymptomatic CT infection had a representative frequency, which was more pronounced among young attendees with an STI diagnosis and their sexual partners, to whom screening should be offered. Issues of age limits for screening and whether screening should be directed to males in non-STI clinic settings should be carefully assessed.

Screening for chlamydia: are you doing it?

This retrospective study evaluates the implications of offering routine chlamydia screenings to women ages 16 to 25 attending a primary care clinical setting. Results found that routine screenings significantly increased the number of women screened, enabling early identification and treatment of affected women and potentially reducing infection rates.

Screening for Chlamydia trachomatis infection among infertile women in Saudi Arabia

BACKGROUND

Chlamydia trachomatis infection is a worldwide-distributed sexually transmitted infection that may lead to infertility.

OBJECTIVES

This study aims to report the prevalence of Chlamydia trachomatis infection among infertile women in Saudi Arabia.

PATIENTS AND METHODS

A community-based study carried out at the obstetrics and gynecology clinic at Jazan General Hospital, Saudi Arabia. The study group included 640 Saudi infertile women who were aged between 18 and 40 years and who attended the gynecology clinic for infertility examination throughout 1 year of study (from July 1, 2011 to June 30, 2012). The randomized control group included 100 Saudi fertile women who attended the obstetrics clinic for routine antenatal care. All recruited women were screened for chlamydia infection by enzyme-linked immunosorbent assay (ELISA) for detection of serum-specific antibodies and then retested by the McCoy cell culture technique.

RESULTS

The prevalence of Chlamydia trachomatis infection among infertile women was high, at 15.0%. The rate of chlamydia infection detected by ELISA was 9.84%, and it was 12.03% by the culture method (P = 0.2443).

CONCLUSION

The high prevalence of Chlamydia trachomatis infection among Saudi infertile women demands a national screening program for early detection among infertile couples. ELISA is available as a simple screening test alternative to the culture method.

Association of anti-Chlamydia antibodies with ectopic pregnancy in Benin city, Nigeria: a case-control study

BACKGROUND

Ectopic pregnancy remains a major public health problem especially in many developing countries where it is a significant contributor to pregnancy related morbidity and mortality.

OBJECTIVE

To determine the association between prior Chlamydia trachomatis infection and the risk of ectopic pregnancy.

METHODS

A case-control study from two tertiary health care facilities in Benin City, Nigeria. Ninety eight women with ectopic pregnancy (cases) and another 98 women with uncomplicated intrauterine pregnancy (controls) matched for age, were interviewed using a semi-structured questionnaire and evaluated for serological evidence of prior Chlamydia trachomatis infection.

RESULTS

The antibody titres in cases (48%) were significantly higher than in controls (16.3%) (p<0.001). However, the association between Chlamydia antibodies and ectopic pregnancy was attenuated when the effects of indicators of previous pelvic infections, socio-demographic characteristics, contraceptive and sexual history were controlled for. Primary level of education (OR = 6.32; CI, 2.31 - 17.3), three or more lifetime sexual partners (OR = 5.71; CI, 2.39 - 13.65) and prior history of vaginal discharge (OR = 5.00; CI, 2.03 - 12.3) were more likely to be associated with ectopic pregnancy than with the presence of antibodies to Chlamydia trachomatis (OR = 2.82; 95% CI, 1.33 - 5.95). The Population Attributable Risk was 30.9%.

CONCLUSION

Chlamydial infections play only a limited role in the pathogenesis of ectopic pregnancy.

Non-injection and injection drug use and STI/HIV risk in the United States: the degree to which sexual risk behaviors versus sex with an STI-infected partner account for infection transmission among drug users

We used the National Longitudinal Study of Adolescent Health (N = 14,322) to measure associations between non-injection crack-cocaine and injection drug use and sexually transmitted infection including HIV (STI/HIV) risk among young adults in the United States and to identify factors that mediate the relationship between drug use and infection. Respondents were categorized as injection drug users, non-injection crack-cocaine users, or non-users of crack-cocaine or injection drugs. Non-injection crack-cocaine use remained an independent correlate of STI when adjusting for age at first sex and socio-demographic characteristics (adjusted prevalence ratio (APR): 1.64, 95 % confidence interval (CI): 1.16-2.31) and sexual risk behaviors including multiple partnerships and inconsistent condom use. Injection drug use was strongly associated with STI (APR: 2.62, 95 % CI: 1.29-5.33); this association appeared to be mediated by sex with STI-infected partners rather than by sexual risk behaviors. The results underscore the importance of sexual risk reduction among all drug users including IDUs, who face high sexual as well as parenteral transmission risk.

Spolno Prenosljive Okužbe Z Bakterijo Chlamydia Trachomatis V Sloveniji / Sexually Transmitted Infections With The Bacteria Chlamydia Trachomatis In Slovenia

Namen:Namen prispevka je na osnovi sistematičnega pregleda objavljenih raziskav oceniti prevalenco genitalnihokužb z bakterijo Chlamydia trachomatis v Sloveniji.

Metode:Pregledana je bila literatura v dveh elektronskih podatkovnih zbirkah, in sicer v zbirki PubMed z uporabokombinacije ključnih besed »chlamydia« in »Slovenia« ter v zbirki Cobiss Slovenija s pomočjo ključnih besed»klamidija«, »chlamidia« in »chlamydia«. Vključene so raziskave, ki so bile v navedenih zbirkah vpisane do vključnokonca novembra 2011 in so vsebovale izsledke o pogostosti klamidijskih okužb med prebivalci Slovenije.

Rezultati:V obdobju od leta 1980 do vključno konca novembra 2011 je bilo objavljenih 18 raziskav, ki so ustrezaleiskalnim merilom. Večina raziskav je bila izvedena na različnih skupinah prebivalcev Slovenije in ne na verjetnostnihnacionalnih vzorcih. Klamidijska okužba je bila ugotovljena v 0-19% primerih. Pri preiskovancih z nekaterimi stanji,ki so lahko povezana z višjo prevalenco spolno prenosljivih okužb, je bila klamidijska okužba ugotovljena v 4,9-19%,pri tistih, ki takšnih stanj niso imeli opisanih, pa v 0-16,5%. Pet raziskav je bilo končanih po letu 2000 in pri teh jebila klamidijska okužba ugotovljena v 0-6,5%. Največ okuženih je med starimi 20 in 24 let.

Zaključki:Chlamydia trachomatis je pomembna povzročiteljica spolno prenosljivih okužb v Sloveniji. Večineklamidijskih okužb zaradi nizkih stopenj testiranja ne prepoznamo in tako zamujamo številne priložnosti za zdravljenjein preprečevanje kasnih posledic, predvsem za reproduktivno zdravje žensk

Systematic screening with information and home sampling for genital Chlamydia trachomatis infections in young men and women in Norway: a randomized controlled trial

BACKGROUND

As most genital Chlamydia trachomatis infections are asymptomatic, many patients do not seek health care for testing. Infections remain undiagnosed and untreated. We studied whether screening with information and home sampling resulted in more young people getting tested, diagnosed and treated for chlamydia in the three months following the intervention compared to the current strategy of testing in the health care system.

METHOD

We conducted a population based randomized controlled trial among all persons aged 18-25 years in one Norwegian county (41 519 persons). 10 000 persons (intervention) received an invitation by mail with chlamydia information and a mail-back urine sampling kit. 31 519 persons received no intervention and continued with usual care (control). All samples from both groups were analysed in the same laboratory. Information on treatment was obtained from the Norwegian Prescription Database (NorPD). We estimated risk ratios and risk differences of being tested, diagnosed and treated in the intervention group compared to the control group.

RESULTS

In the intervention group 16.5% got tested and in the control group 3.4%, risk ratio 4.9 (95% CI 4.5-5.2). The intervention led to 2.6 (95% CI 2.0-3.4) times as many individuals being diagnosed and 2.5 (95% CI 1.9-3.4) times as many individuals receiving treatment for chlamydia compared to no intervention in the three months following the intervention.

CONCLUSION

In Norway, systematic screening with information and home sampling results in more young people being tested, diagnosed and treated for chlamydia in the three months following the intervention than the current strategy of testing in the health care system. However, the study has not established that the intervention will reduce the chlamydia prevalence or the risk of complications from chlamydia.

Prevalence and associated factors for four sexually transmissible microorganisms in middle-aged men receiving general prostate health checkups: a polymerase chain reaction-based study in Korea

PURPOSE

To investigate the prevalence of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Mycoplasma genitalium (MG), and Ureaplasma urealyticum (UU) in first-voided urine samples and to determine the factors associated with positivity for sexually transmissible microorganisms in healthy, middle-aged Korean men.

MATERIALS AND METHODS

Five hundred fifty-one men who came to the hospital for a general prostate health checkup were tested between August 2011 and December 2011. PCR assays for CT, NG, MG, and UU were done with first-voided urine samples and the prevalence of microorganism positivity and association with several clinical parameters were evaluated.

RESULTS

The mean age of the men studied was 50.8±4.7 years. Among the 551 men, 72 (13.1%) had a positive result for at least one microorganism; one (0.2%) had two different species. The overall prevalence of asymptomatic sexually transmitted infections was 11.1% (61/551). The prevalence rates of CT, NG, MG, and UU infection in the general population were 0.4% (2/551), 0.0% (0/551), 1.0% (6/551), and 11.8% (65/551), respectively. CT-positive patients had a lower mean age than did CT-negative patients. There were no significant differences in symptoms by positivity of each microorganism.

CONCLUSIONS

We checked the prevalence rates of four microorganisms, the proportion of symptomatic people, and the association of microbes, age, and symptoms, as the baseline data for Korean middle-aged men. In this population, CT, NG, MG, and UU infections do not seem to be symptomatic. However, the potential role of CT in young men and of UU in middle-aged men with a high rate of detection should be studied continuously as a source of opportunistic infection.

A multiplexed microfluidic PCR assay for sensitive and specific point-of-care detection of Chlamydia trachomatis

BACKGROUND

Chlamydia trachomatis (Ct) is the most common cause of bacterial sexually transmitted diseases (STD) worldwide. While commercial nucleic acid amplification tests (NAAT) are available for Ct, none are rapid or inexpensive enough to be used at the point-of-care (POC). Towards the first Ct POC NAAT, we developed a microfluidic assay that simultaneously interrogates nine Ct loci in 20 minutes.

METHODOLOGY AND PRINCIPAL FINDINGS

Endocervical samples were selected from 263 women at high risk for Ct STDs (∼35% prevalence). A head-to-head comparison was performed with the Roche-Amplicor NAAT. 129 (49.0%) and 88 (33.5%) samples were positive by multiplex and Amplicor assays, respectively. Sequencing resolved 71 discrepant samples, confirming 53 of 53 positive multiplex samples and 12 of 18 positive Amplicor samples. The sensitivity and specificity were 91.5% and 100%, and 62.4% and 95.9%, respectively, for multiplex and Amplicor assays. Positive and negative predictive values were 100% and 91%, and 94.1% and 68.6%, respectively.

CONCLUSIONS

This is the first rapid multiplex approach to Ct detection, and the assay was also found to be superior to a commercial NAAT. In effect, nine simultaneous reactions significantly increased sensitivity and specificity. Our assay can potentially increase Ct detection in globally diverse clinical settings at the POC.

Evaluation of the new test VERSANT CT/GC DNA 1.0 assay for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae in urine specimens

Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) are the two most common sexually transmitted bacterial infections in developed countries. The purpose of the present study was evaluating a new system for CT/GC detection in urine specimens. A total of 700 urine specimens were obtained from patients attending the STD Outpatients Clinic of St. Orsola University Hospital, Bologna, Italy. Samples were tested by VERSANT® CT/GC DNA 1.0 Assay (Siemens Healthcare Diagnostics Inc., Tarrytown, NY), a multiplex Real-Time PCR assay, for simultaneous CT/GC detection. Results obtained by VERSANT assay were compared with those obtained by culturing genital secretions of the same patients. Moreover, urine specimens testing positive in VERSANT assay were retested by in-house PCR assays, used as confirmatory tests. VERSANT® CT/GC DNA 1.0 Assay performed with 99.4% and 99.2% of specificity for GC and CT detection, respectively, whereas sensitivity was 100% both for CT and GC. Culture methods were 100% specific, but far less sensitive than VERSANT assay. VERSANT® CT/GC DNA 1.0 Assay demonstrated to be a highly sensitive and specific technique for CT/GC detection.

Urine screening for Chlamydia trachomatis during pregnancy

OBJECTIVE

To compare the rates of Chlamydia trachomatis detection using urine and cervical secretions from pregnant women at our institution.

METHODS

A large cross-sectional sample of pregnant women (N=2,018) at 35-37 weeks of gestation were tested for C trachomatis with both endocervical and urine sampling using the Aptima Combo 2 Assay.

RESULTS

A prevalence of 4.3% and 4.1% were found for Chlamydia endocervical and urine samples, respectively. There was no difference between the two tests by McNemar's test (-0.02%, 0.32%; P=.083). There was excellent correlation between the tests found by the κ statistic (0.982 [0.961-1.000]).

CONCLUSION

Urine sampling for C trachomatis is equivalent to endocervical sampling in pregnancy using the Aptima 2 Combo Assay.

LEVEL OF EVIDENCE

II.

Distribution of Chlamydia trachomatis serotypes in clinical urogenital samples from north-eastern Croatia

The purpose of this study was to determine prevalence of Chlamydia trachomatis (Ct) urogenital infection and its serotype distribution from clinical samples in north-eastern Croatia. During a 3-year period, 2,379 urogenital samples were analyzed by real-time polymerase chain reaction (A group), while 4,846 genital swabs were analyzed by direct fluorescent antibody test (B group). 132 Ct positive specimens were genotyped by omp1 gene sequencing. The prevalence rate of Ct was 3.2 % in A and 1 % in B group. The most prevalent chlamydial genotype was E (44 %), followed by F (33 %), K (11.5 %), G (8 %), J/UW (5.3 %), D-IC (4.4 %), D-B120 (1.8 %), and B/IU, J/IU, Ia/IU (0.9 % each) serotypes. Single-nucleotide polymorphisms (SNPs) of omp1 gene were detected in E, K, and G serotypes. Some of these SNPs (C/T at position 272 and G/A at position 813 in E strain; C/T at position 884 in D strain) might represent novel omp1 variants.

Diagnosis of Chlamydia infection in women

OBJECTS

Chlamydia (Chlamydia trachomatis) is a common sexually transmitted infection that places a heavy burden on women and neonatal health. To avoid severe sequelae such as female infertility, ectopic pregnancy, neonatal infection, such as ophthalmitis, and chronic pelvic pain prompt and appropriate antibiotic treatment seems the best policy in treating this group of patients. However, adequate treatment is not easy because many factors can interfere with an early and rapid identification of Chlamydia infection, including complicated mixed microflora of the vagina and cervix, a nonuser-friendly detection system, and the time required for identification, even with the combination of specific complaints and a high level of clinical alertness. When dealing with a female patient in a point-of-care (POC) clinic, we need to find the best strategy to provide the most efficient way to detect this infection.

MATERIALS AND METHODS

Totally five traditional methods and advanced technologies used for the diagnosis of Chlamydia infection in women were reviewed. A criterion proposed by World Health Organization with an acronym of ASSURED, representing affordable price, high sensitivity, high specificity, user-friendly design, rapid process, minimal equipment, and delivered-or-not, was used to reexamine these tools if they are the best tools. A multiplexed microchip-based immunoassay was evaluated as a potential tool. The ASSURED score was compared and a Chi-square test with a p value less than 0.05 was considered significant.

RESULTS

Traditional methods, such as symptoms approach, microscopic examination, and microorganism culture that have been broadly used once, are affordable, simple, and equipment-free but their relatively low sensitivity and specificity limit their use as a test of POC setting for these infected women. On the other hand, advanced technologies, such as antigen detection by immunoassay and nucleic acid amplification tests, have contributed to major progress in the diagnosis of Chlamydia because of its accuracy, convenience, and time saving. However, nucleic acid amplification tests are too expensive, so they cannot be accepted as a screening tool in a developing country. The only significant finding with p value less than 0.01 was achieved when a more sensitive immunoassay system developed successfully as a test of POC setting.

CONCLUSIONS

Eventually, advances in laboratory techniques will satisfy our needs to detect Chlamydia infection economically and instantly. Microarray chips might be a relatively rapid, easy, inexpensive, and sensitive tool to detect many pathogens, including Chlamydia, using a one-time vaginal sampling process, which might make a POC policy possible.